Checked Bags: Yes Water for babies is allowed in reasonable quantities in carry-on bags. Remove this item from your carry-on bag to be screened separately from the rest of your belongings. Please see traveling with children for more information.

Yes, you can bring a sippy cup containing water through airport security and onto a plane, provided you are traveling with an infant or toddler. The TSA and most international security agencies (including those in the UK and EU) classify water, formula, breast milk, and juice for young children as "medically necessary liquids." This means they are exempt from the standard 3.4-ounce (100ml) limit. You do not need to fit the sippy cup into your quart-sized clear bag, but you must declare it to the security officer at the start of the screening process. The officer will likely perform an additional check, such as an Explosive Trace Detection (ETD) swipe on the outside of the cup or using a vapor analyzer. To make the process smoother, it is helpful to have the cup easily accessible in your bag. If you are a solo adult without a child, you cannot bring a sippy cup of water through; you must empty the cup before the checkpoint and refill it at a water station once you have cleared security.